This post marks the seventh installment in my series on the nature of the mind. In this post, we will critically evaluate Churchland’s eliminative materialism. For requisite context, it would be best to check out Parts 1, 2, 3, and 4, and 5, and 6. Let’s get this bread!
5.1 Churchland’s Central Arguments
In the following sections, I outline Churchland’s central arguments excerpted from his “Matter and Consciousness.”
5.1.1 From Explanatory Poverty
P1: Folk psychology is afflicted by widespread and long-standing failures in explanation and prediction.
P2: An approach afflicted by longstanding and widespread failures in explanation and prediction should be rejected.
C (P1, P2): Therefore, folk psychology should be rejected.
5.1.2 Pessimistic Induction from Conceptual History
P1: Most of our past folk frameworks (theories, concepts, etc) have been wrong.
P2: If most past folk frameworks have been wrong, then probably folk psychology is wrong.
C (P1, P2): Probably, folk psychology is wrong.
5.1.3 From Utility
P1: There are so many more ways that neuroscientific explanations may proceed if they are not required to conform to folk psychological theories (i.e. eliminative materialism has high utility for neuroscience).
P2: If P1 is true, then eliminativism is likely true.
C (P1, P2): Therefore, eliminativism is likely true.
5.2 Critical Appraisal of Churchland’s Central Arguments
In the following sections, I critically evaluate Churchland’s central arguments.
5.2.1 From Explanatory Poverty: Evaluation
Criticism One: The explanatory adequacy of folk psychology
Premise one seems false. Consider the following explanation:
Joe desires to make a good blog post, and he believes that critiquing Churchland’s argument from explanatory poverty is one way to help ensure that this desire is fulfilled. He thinks that typing on the computer will facilitate this critique, and then decides, on the basis of his thoughts, beliefs, and desires, to type on his computer.
This seems perfectly adequate as an explanation of my behavior. Now, it may not be a complete explanation, but that isn’t its intent in the first place. It is not a necessary condition for an explanation’s success that it be a complete account of the entirety of some phenomenon.
In general, the explanatory deficiencies Churchland pinpoints (explanations of sleep, mental illness, and so on) simply lie outside the scope of folk psychological explanation. But a framework’s inability to explain something that is inherently beyond its scope is not an explanatory deficiency on the part of the framework, any more than (say) general relativity’s inability to explain the origins of domestic terrorism counts as a deficinecy in general relativity.
Criticism Two: Presupposing folk psychology is a theory
Churchland’s argument presupposes that folk psychology is a theoretical framework rather than the very data for which any theoretical framework must account. But without justifying this presupposition, Chruchland’s argument is itself unjustified.
More importantly, this assumption seems implausible. It seems that beliefs, desires, pains, wishes, hopes, and thoughts are the very data that any theory of mind needs to explain. It seems implausible that (say) we come to recognize some phenomenon in need of explanation (such as inner states), and, upon trying to explain or account for such a phenomenon, posit theoretical entities called “beliefs,” “desires,” “thoughts,” and so on to explain and/or predict the raw data. It seems, rather, that such concepts simply denote the very data for which any theory must account.
5.2.2 Pessimistic Induction from Conceptual History: Evaluation
Criticism One: A relevant difference between past folk theories and folk psychology
Churchland presupposes that past folk theories are relevantly similar to folk psychology so as to legitimately facilitate an inductive generalization from their failure to folk psychology’s probable failure. But this presupposition seems false, since there seem to be relevant differences between past folk theories and folk psychology that delegitimize this inductive generalization.
One such relevant difference is that past folk theories almost invariably involved concocting some unobservable explanatory account or positing unobservable entities that are clearly beyond our ordinary and direct awareness of things. For instance, phlogiston is an entity that clearly was not observable. The celestial spheres of ancient cosmology were well beyond our ordinary and direct awareness. Caloric was a theoretically postulated fluid that underlies the transmission of heat and while the heat itself was directly experienced, the caloric fluid was not and was invoked as a theoretical posit.
But folk psychology seems relevantly dissimilar to these folk theories in that it concerns objects of our direct, immediate, unfaltering awareness. Folk psychological notions concern our inner, directly accessible states rather than indirect, unobservable postulations in extramental reality. But given that direct awareness and immediate access is a relevant difference between folk psychology and past folk theories, we cannot inductively infer folk psychology’s failure from the failure of past theories.
Criticism Two: Inter-theoretic entity preservation
A general lesson from conceptual history is that, when a more sophisticated scientific theory replaces a false folk theory, there was nevertheless inter-theoretic entity preservation. So, although we come to have a different understanding of some entity or phenomenon, the entity or phenomenon itself is (in general) still taken to exist. We did not jettison our belief in the existence of stars upon replacing our folk conception of stars; we did not jettison our belief in the existence of space upon replacing our folk conception of space; we did not jettison the very existence of heat upon replacing our folk caloric theory; and so on.
But given such inter-theoretic entity preservation, Churchland’s inductive generalization is far too hasty. He is unwarranted in inferring that, likely, our folk psychological entities don’t exist; rather, he is only entitled (at best) to infer that our understanding of such entities will be altered. Hence, his desired conclusion (namely, that there likely are no such things as desires!) does not follow and is actually contravened by the conceptual history of inter-theoretic entity preservation.
Criticism Three: Pessimistic induction is self-defeating
Arguably, Churchland’s argumentative structure is self-defeating. For consider the following argument:
P1: Most past theories concerning the nature of the mind have been wrong.
P2: If most past theories concerning the nature of the mind have been wrong, then eliminative materialism is likely wrong (since eliminative materialism is a theory concerning the nature of the mind).
C (P1, P2): Therefore, eliminative materialism is likely wrong.
5.2.3 From Utility: Evaluation
Criticism One: Non-sequitur
Arguably, it simply does not follow that x is likely true from the fact that x is useful to a discipline. In population genetics, it is often very useful (i) to model populations as having infinitely many members, and (ii) to assume that populations are in Hardy-Weinberg equilibrium; in oceanography and fluid dynamics, it is often very useful to assume (i) that the ocean is infinitely deep, and (ii) that fluids are continuous substances not composed of discrete, particulate sub-units; and so on. Nevertheless, every single one of these assumptions is not even approximately true. Utility, then, doesn’t seem to track truth in the robust way required for Churchland’s argument. Therefore, merely from the fact that eliminative materialism may be useful to neuroscientific progress, we have little to no reason to think eliminative materialism is true.
Criticism Two: The essentiality of folk psychology to neuroscience
The fundamental problem with Churchland’s argument is that eliminative materialism actually seems to remove the very possibility of neuroscience. The reliability, success, and progress of neuroscience crucially relies upon the existence of and reliable access to subjective, inner, qualitative, common sense psychological states.
As Feser puts it,
The relevant micro-level phenomena uncovered by science cannot even be identified or understood without constant reference to the commonsense macro-level phenomena they underlie, so that the latter cannot coherently be eliminated in favor of the former. Hence, consider any claim that some mental phenomenon M is correlated with some brain process B, and ought to be eliminated from our ontology altogether and replaced by B. For any such argument to get off the ground, we first have to be able to identify B, as opposed to some other neural process, as the relevant process.6
But the only way to know that M is correlated with B as opposed to some other brain process is to rely upon the introspective, commonsense report of the person whose brain we are studying. If the neuroscientist is wrong about his or her presupposition of the reliably accurate introspective report of the person’s own mental state, then the very evidential foundation upon which the neuroscientific, correlative evidence is based collapses.
In the next and final post in this series, we will summarize the findings of the previous six posts and make some final plausibility determinations.
And, lastly, another meme:
Paul Churchland: Minds don’t exist.